1. Field of the Invention
This invention pertains to expandable camper bodies, and in particular to a camper body composed of forward and aft sections, the aft section capable of a telescoping movement within the forward section and the support tracks for the aft section capable of being raised and folded hydraulically for ease of transport.
2. Description of the Prior Art
The prior patent art is replete with examples of expandable camper bodies and house trailers. However, to the best of the inventor's knowledge, none of the prior art devices has been a commercial success. An analysis of the prior art indicates that the basic problems relate to the cost effectiveness of the prior art designs. Most are too expensive to manufacture, too difficult to operate and provide too little additional space relative to the additional costs. For example, in U.S. Pat. No. 3,212,810, a collapsible house trailer is described which collapses both vertically and horizontally. The provision of vertical expansion adds a little to the value of the trailer, but a substantial amount to the cost of production. The longitudinal expansion of this trailer results in a separation of its front and rear wheels, which bear the load of its weight. To offset the change in weight and balance distribution, a strong expandable undercarriage or structural frame must be provided, though details are not shown. Furthermore, the provision of vertical and horizontal expansion creates, in the fully collapsed state, a situation in which three walls overlap on portions of each side of the trailer, thereby costing a substantial loss of useful space relative to the gross space. U.S. Pat. Nos. 2,902,312 and 2,732,251 each teach horizontally, latitudinally, expandable house trailers. The first patent requires jacks under both fixed and movable sections for support, and requires a complicated folding floor mechanism. The second also has a folding floor which interferes with use of the trailer in the collapsed position. Furthermore, U.S. Pat. No. 2,732,251 requires an extensive and intricate hydraulic system for its operation. It is clear that the trailer of this invention is too expensive to be practical. Among the recent patent art, U.S. Pat. No. 3,740,088 illustrates telescopic end sections for a trailer. This is a typical example of a non-cost-effective design, in that the additional bunk space provided does not justify the addtional cost of fabrication, U.S. Pat. No. 3,915,492 teaches a trailer that is expandable horizontally either along its latitudinal axis or along its longitudinal axis. The embodiments taught in this patent are mechanically complex and somewhat incomplete. It is unclear how the roof extends to cover the extended areas, how the utility lines are handled and how the extended areas are supported. Furthermore, a considerable amount of weight is added to the trailer and considerable internal height is lost with its double flooring arrangement.
The expandable camper body of the present invention is specifically designed to overcome the limitations of prior art designs by providing mechanical simplicity with sturctural integrity in an inexpensive, cost-effective embodiment. The present invention does not utilize vertical expansion because the additional structural requirements are not worth the minimal additional useful space. Horizontal expansion along the latitudinal axis presents its own problems. If both sides expand outwardly, some mechanical systems must be duplicated. If one side expands only, problems of tracking and weight and balance arise. Hence, the present invention is designed for horizontal expansion along the longitudinal axis of the camper body. This embodiment lends itself to simple mechanical systems and minimal operational problems.
This invention relates to camper bodies, and is directed particularly to a camper body which, when expanded, approximately doubles in size. The principal object of this invention is to provide a camper body which, when retracted, is relatively small and easy to transport and can be compacted to approximately one half its extended volume to provide the least visual obstruction and wind resistance in transport from place to place.
A more particular object of the invention is to provide a camper body which comprises a telescoping aft section so arranged as to permit simplified, inexpensive construction and ease of expansion when parked.
Another object is to provide improved and simplified track means interconnecting the forward and aft sections of the camper body for relatively simple horizontal movement in expanding and retracting the camper body such that the expansion and retraction may be performed by one person in a short period of time.
Another object of the invention is to provide an expandable camper body which automatically secures the forward and aft sections in tight interfitting engagement at the fully extended and fully retracted positions for structural integrity.
Another object of this invention is to provide a novel means for guiding the movable aft section of the camper body and a power driven means for effecting such movement, so that virtually no manual labor is required to expand or retract that section, and so that the expansion and retraction may be effected with minimum effort and a few minutes time.
Another object of this invention is to provide an improved hydraulic fluid pressure system for operating the expansion and retraction of the aft section of an expandable camper body.